陕北±800 kV换流站高填方湿陷性黄土地基处理方案研究

Researoh on Treatment of Collapsible Loess Foundation with High Fill in±800 kV Shanbei Converter Station

陕北±800 kV换流站用地为原循环工业经济园区挖黄土梁卯、填深沟给出的一块台阶式场地,场地覆盖一层厚度0~50 m的素填土,密实度差异较大,土质极不均匀,填土完成约5年半时间,是一种欠固结土,在其自身重度和大气降水的入渗作用下有自行密实的特点,影响位于填方区建(构)筑物地基的承载力和稳定性。基于该工程特殊的岩土地质情况,除挖方区采用天然地基外,从处理填方区大面积欠固结土和消除部分地基土湿陷性、提高地基土承载力、减小场地沉降变形的角度,对不同地基处理及桩基方案进行技术经济综合比选,提出适合本工程的经济合理的地基处理方案。

±800 kV Shanbei Converter Station is located in filling and excavation reconstruction project sites which in mountain ridge and valley.The thickness of plain fill in this area is 0~50 m,the completion time of filling is 5.5 years,which is an under consolidated soil.The soil quality is unstable,it will affect the stability of building foundation.Based on the special geotechnical conditions of this project,this paper compares several foundation treatment schemes from treating large area under-consolidated soil,eliminating the collapsibility of partial foundation soil,improving the base bearing capacity and reducing foundation settlement.A recommended foundation treatment scheme which is characterized by rational technology,appropriate construction period and low investment has been put forward.